Magnetic Pen

ABSTRACT

A magnetic pen can be used in drawing arbitrary characters, figures, and symbols on a magnetic panel for a display by applying a magnetic field. The magnetic pen includes a body that includes an end portion. A holder made of a magnetic material is attached to the end portion and an internal space is formed in the holder. The holder includes a bottom portion formed with an opening and a side portion connected to the bottom portion. A magnet is arranged in the internal space of the holder. The magnet is received in a space formed by the bottom portion and the side portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Application No. 2018-059123, filed on Mar. 27, 2018 and is a continuation-in-part of U.S. application Ser. No. 15/663,287, filed Jul. 28, 2017, which claims priority to Japanese Application No. 2016-148086, filed on Jul. 28, 2016. All of the above applications are hereby incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a magnetic pen, e.g., one that is capable of drawing arbitrary characters, figures, symbols, etc. by applying a magnetic field to a display panel including magnetized display bodies.

BACKGROUND

When a magnetic pen with a magnet attached to the end portion is drawn with respect to a magnetic panel including magnetized display bodies, the magnetic field of the magnetic pen acts on the display bodies so that character, figure, symbol, or the like corresponding to the moving track of the magnetic pen can be displayed at a magnetic panel. For a magnetic pen that applies the magnetic field to the magnetic panel, Japanese patent publication No. 2009-935, for example, discloses a magnetic pen that weakens the pressure in writing applied to the magnetic panel with a simple structure. In addition, Japanese patent publication No. 2007-256891, Japanese patent registration No. 2717536, and Japanese patent registration No. 4089808 each discloses a magnetic panel that forms a recording layer by enclosing magnetic particles in microcapsules.

The conventional magnetic pen has the following problems. FIG. 12 shows a sectional view of an end portion of the conventional magnetic pen. A cylindrical holder 1 made of a nonmagnetic material such as plastic, resin or brass or the like is provided at the end portion of the magnetic pen to accommodate a magnet 2 in an internal space of the holder 1. The magnet 2 is arranged to protrude somewhat from an edge 3 of the holder 1. Lines of magnetic force 4 are formed from an N pole to an S pole of the magnet 2 to act on the magnetic panel (not shown) to move cataphoretically display bodies such as a microcapsule of the magnetic panel.

In the conventional magnetic pen, the lines of magnetic force 4 from the N pole to the S pole protruding from the edge 3 of the holder 1 spread out in the radial direction of the holder 1, in other words lines of magnetic force 4 includes lots of portions 4 a which are spread out in the horizontal direction, as the result when characters or figures are drawn on the magnetic panel, the outlines of characters or figures are blurred, lines are exuded, and edges are unclear. For example, when drawing the Japanese word for “rice”, the four squares were sometimes crushed.

Furthermore, the thickness of line segment such as characters displayed on the magnetic panel depends on the size and shape of the end portion of the magnetic pen. For example if the magnet size in the width direction is increased, the thickness of line segment on the magnetic panel is thickened. However, when the width of the magnet 2 in the magnetic pen as shown in FIG. 12 is spread, the lines of magnetic force 4 a extending in the horizontal direction are greater than that of the vertical direction, not only the edges of line segments are blurred, it may happen that character is erased while drawing.

SUMMARY

Embodiments of the present invention solve such conventional problems and provide a magnetic pen that enables to draw clear images as compared with the conventional art.

In the present invention, a magnetic pen for a magnetic panel comprises a holder made of a magnetic material attached to an end portion of the magnetic pen. An internal space is formed in the holder. A magnet is arranged in the internal space of the holder so that at least the S pole and the N pole are opposite the magnetic panel.

In some embodiments, the surface of the magnet is located so as to be recessed from the edge of the holder.

In some embodiments, the surface of the magnet is at the same position as the edge of the holder.

In some embodiments, the magnetic pen further comprises an adjusting mechanism for adjusting a position of the magnet with respect to the edge of the holder.

In some embodiments, the magnet includes a plurality of S poles and a plurality of N poles so as to face the magnetic panel.

In some embodiments, the plurality of S poles and the plurality of N poles are arranged in rotational symmetry with respect to the axial center of the holder.

In some embodiments, the magnetic pen further comprises a magnetic member arranged in the internal space of the holder adjacent to the magnet.

In some embodiments, the magnetic member is disposed at the axial center of the holder.

In some embodiments, the magnetic pen further comprises a grip portion connected to the end portion. The end portion is connected to the grip portion through an universal joint.

In some embodiments, the universal joint provides a two-dimensional or three-dimensional connection so that the axis of the holder is substantially perpendicular to the plane of the magnetic panel.

In some embodiments, the end portion includes a sliding guide for sliding on the surface of the magnetic panel and the sliding guide is connected to the universal joint.

In some embodiments, the universal joint is attached so as to offset from the center of the holder.

In some embodiments, the universal joint is attached coaxially with the center of the holder.

In some embodiments, the universal joint is comprised of an elastic member.

In some embodiments, the magnetic pen is configured such that the end portion is rotatable about an axis.

Furthermore in the present invention, a magnetic pen for a magnetic panel comprises a holder made of a magnetic material attached to an end portion of the magnetic pen. An internal space is formed in the holder. A magnet is disposed in the internal space of the holder. A surface of the magnet opposite the magnetic panel is at a position recessed from an edge of the holder.

According to the present invention, since the magnet of the S pole and the N pole are arranged in the holder of the magnetic material at the end portion so as to face the magnetic panel, the lines of magnetic force are acted effectively on the magnetic panel compared with the conventional magnetic pen, as the result characters with sharp edges and less exuding can be drawn on the magnetic panel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a front view of a magnetic pen according to a first embodiment of the present invention.

FIG. 2 shows a perspective view of the magnetic pen according to the first embodiment of the present invention.

FIG. 3, which includes FIGS. 3A-3C, shows an end portion of the magnetic pen according to the first embodiment of the present invention. FIG. 3A shows a plan view of the holder at the end portion and its cross-sectional view of line A-A, FIG. 3B shows a plan view of the holder in which magnets are held and its cross sectional view of A-A line, and FIG. 3C shows a perspective view of the holder in which magnets are held.

FIG. 4, which includes FIGS. 4A and 4B, exemplifies a cross-sectional view of a magnetic panel applicable with the magnetic pen according to the first embodiment of the present invention.

FIG. 5, which includes FIGS. 5A and 5B, shows a view for explaining the operation of the magnetic pen according to the first embodiment of the present invention.

FIG. 6, which includes FIGS. 6A-6C, shows a cross-sectional view and a perspective view of the end portion of a magnetic pen according to a second embodiment of the present invention.

FIG. 7, which includes FIGS. 7A-7D, shows a view for explaining the magnetic pen according to a third embodiment of the present invention.

FIG. 8A shows a modified example of the magnetic pen according to the third embodiment of the present invention.

FIG. 8B shows a further modified example of the magnetic pen shown in FIG. 8A.

FIG. 8C shows a modified example of the magnetic pen according to the third embodiment of the present invention.

FIG. 8D shows a modified example of the magnetic pen according to the third embodiment of the present invention.

FIG. 8E shows a further modified example of the magnetic pen shown in FIG. 8D.

FIG. 9, which includes FIGS. 9A-9C, shows a view for explaining a magnetic pen according to a fourth embodiment of the present invention.

FIG. 10, which includes FIGS. 10A-10L, shows various examples for arranging magnets applied to each embodiment of the present invention.

FIG. 11, which includes FIGS. 11A-11D, shows a view for explaining a magnetic pen according to a fifth embodiment of the present invention.

FIG. 12 shows a view for explaining problems of a conventional magnetic pen.

FIG. 13, which includes FIGS. 13A-13F, shows a holder for the magnetic pen according to a sixth embodiment of the present invention.

FIG. 14, which includes FIGS. 14A-14F, shows modified example of the holder according to the sixth embodiment of the present invention.

FIG. 15 shows a cross sectional view of a magnetic pen according to a seventh embodiment of the present invention.

FIG. 16, which includes FIGS. 16A and 16B, shows an enlarged drawing portion of the magnetic pen according to the seventh embodiment of the present invention.

FIG. 17, which includes FIGS. 17A and 17B, shows a modified example of the magnetic pen according to the seventh embodiment of the present invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Next, embodiments of the present invention will be described in detail with reference to the drawings. In a preferred embodiment of the present invention, the magnetic pen includes a magnet at its end portion, and the magnetic pen is enable to draw characters, figures, pictures, and etc. on a magnetic panel by causing magnetic field to act on the magnetic sheet such as a magnetophoretic type or a magnetic reversal type. Please note that the configurations shown in the drawings for explaining the embodiments of the present invention are different from the actual ones.

FIG. 1 shows a front view of a magnetic pen according to a first embodiment of the present invention, and FIG. 2 shows a perspective view of the magnetic pen. The magnetic pen 10 includes a cylindrical grip portion (body portion) 20 for gripping and an end portion 30 connected to the grip portion 20. When the magnetic pen 10 is slid on the magnetic panel 100, characters, figures and the like corresponding to the trajectory of the magnetic pen 10 can be drawn on the magnetic panel 100 by the action of the magnetic field from the magnetic pen 10. Details of the magnetic panel will be described later.

The grip portion 20 is sufficient if it has a length enough for the user to grasp by hand and the material of the grip portion 20 is not particularly limited. For example, the grip portion 20 can be made of a plastic or resin material etc. as well as the material of the conventional magnetic pen. The end portion 30 is coupled with the grip portion 20 and is provided with a magnet for exerting a magnetic field on the magnetic panel 100.

FIG. 3 shows details of the end portion 30. The end portion 30 includes a cylindrical holder 40, which is made of a magnetic material. The magnetic material is, for example, iron, soft iron or the like. A cylindrical internal space 42 is formed in the holder 40 and has a predetermined depth d from a circumferential edge 44. The outer diameter φ of the holder 40 is appropriately selected according to the shape and size of the magnet to be accommodated in the internal space 42.

The end portion 30 further includes a magnet accommodated in the internal space 42. In one preferred example, a pair of cylindrical magnets 50, 52 is accommodated in the internal space 42. The pair of magnets 50, 52 is preferably of the same size. This, however, is not a limitation and the magnets 50, 52 may be different sizes. The outer diameter φ of the magnets 50, 52 is preferably 0.5 mm or more in terms of handling, but it is not necessarily limited to this. From the viewpoint of the lines of magnetic field, about 0.5 to 1.2 mm is practically preferable. As the diameter increases, the edges of letters or the like are likely to be unclear because the lines of magnetic force parallel to the magnetic panel from the magnet increase.

As shown in FIG. 3B, the magnets 50, 52 are accommodated in the internal space 42 so that the S pole and the N pole of each magnet are reversed relationship in their positions. In the illustrated example, the N pole of the magnet 50 is exposed to the side of edge 44 and the S pole of the magnet 52 is exposed to the side of the edge 44. Here, two magnets 50, 52 are accommodated in the holder, but if the number of magnets is increased, the diameter of the holder also increases accordingly, and a thick line can be drawn.

Each magnet 50, 52 has a length in the axial direction shorter than the depth d of the internal space 42. When one end of each magnet 50, 52 contacts with the bottom of the internal space 42, each surface 50 a, 52 a of the other end of the magnets 50, 52 is positioned by Δd recessed from the edge 44 of the holder 40. One end of the magnets 50, 52 is fixed to the bottom of the internal space 42 with an adhesive or the like. Although Δd depends on the strength of the magnetic flux of the magnet and its diameter, it is, for example, about 0.1 to 0.5 mm, preferably about 0 to 0.3 mm. A gap or a space formed between the magnets 50, 52 and the internal space 42 may be filled with a magnetic material such as soft iron or a yoke 58 or the like (see FIG. 10A).

FIG. 4 shows an example of a magnetic panel that the magnetic pen of this embodiment can be used. The magnetic panel 100 includes a top sheet 110, which is a transparent sheet capable of transmitting a magnetic field, for providing the display surface of the magnetic panel, a back sheet 120 opposite the top sheet 110, and a plurality of microcapsules 130 two-dimensionally arranged in the space between the top sheet no and the back sheet 120. The plurality of microcapsules 130 are accommodated in a case (not shown).

Preferably, the microcapsule 130, for example, includes at least one kind of magnetic particles having a particle size of 0.1 μm to 1.0 μm, at least one kind of magnetic particles having a particle size of 1 μm to 20 μM, white nonmagnetic particles such as white titanium oxide, dispersion and additives in a transparent spherical cell. The size of the microcapsules is, for example, 50 to 650 μm. Such a magnetophoretic type magnetic panel is disclosed in, for example, Japanese patent No. 4089808 and has the following features:

A. Small particles are easily reacted in the direction of lines of magnetic force with horizontal lines of magnetic force.

B. In the magnetic pen having the vertical lines of magnetic force, the large and small magnetic particles are reacted to allow the front side to change black for drawing characters.

C. When erasing from the front side of the magnetic panel, if only the horizontal magnetic field lines are applied to the small particles sensitive to the horizontal lines of magnetic force, the small particles migrate in the direction of the lines of magnetic force to change white. At this time, since the large particles rarely react, they remain “black”, and the black can be seen through from the front side, so that it does not completely become white, which generates decrease in contrast.

D. In order to erase characters, it is sufficient to react horizontal lines of magnetic force. On the contrary, a magnetic pen having horizontal lines of magnetic force erase the written characters by itself immediately, which causing defects.

One microcapsule 130 forms one pixel. For example, as shown in FIG. 4B, when the magnetic field is applied to the microcapsule 130 by the magnetic pen 10 on the top sheet no, as described above, in response to the lines of magnetic force in the vertical direction from the magnetic pen, the black magnetic particles in the microcapsules 130 migrate to the front surface. In this manner, when the magnetic pen 10 is moved on the top sheet no, the magnetic particles in the microcapsules 130 migrate in accordance with the movement to form images. On the other hand, when erasing the images, an erasing magnet (not shown) is slid on the top sheet no, and small particles migrate to the front side in response to the lines of magnetic force in the horizontal direction from the erasing magnet to erase the images. In this case, it is desirable that a certain clearance is provided between the erasing magnet and the top sheet no so as to apply a large amount of horizontal lines of magnetic force to the magnetic panel.

Note that the microcapsule 130 is not necessarily limited to the above structure. For example, the microcapsule 130 may include permanent magnet particles in a transparent spherical cells and the permanent magnet particle may be magnetized so as to have N pole and S pole. The magnetic panel may be erased from the front side or back side. For example, the permanent magnet particles of N pole may be painted black, and the permanent magnet particles of S pole may be painted white, and the permanent magnet particles can move freely within the cell according to the magnetic field from the magnetic pen or erasing magnet.

In addition to the magnetophoresis type, the magnetic panel may be a magnetic reversal type magnetic sheet. Further, the magnetic panel 100 may erase the drawn images by applying the magnetic field from the top sheet no or may erase the drawn images by applying the magnetic field from the back sheet 120.

The operation of the magnetic pen 10 according to the embodiment will be described. FIG. 5A schematically shows the lines of magnetic force generated by the magnets 50, 52 in the holder 40 according to this embodiment. In this embodiment, since the surfaces of the magnets 50, 52 are disposed so as not to protrude from the edge 44 of the holder 40 of a magnetic material, the lines of magnetic force 60 extending from the N pole of the magnet 50 to the S pole of the magnet 52 is converged within the radial direction so as not to exceed the holder 40. In other words, the lines of magnetic force from the outermost shell of the N pole of the magnet 50 enters the S pole via the side wall 46 a of the holder 40, whereas the lines of magnetic force from the N pole of the magnet 52 enters the S pole of the magnet 52 via the side wall 46 b of the holder 40, so the lines of magnetic force are confined in the radial direction. That is, the lines of magnetic force from the N pole surface of the magnet 50 to the S pole surface of the magnet 52 extend in the vertical direction and are restricted within the radius of the holder 40, and the microcapsules 130 as shown in FIG. 4 are acted by the restricted lines of magnetic force. As the result, the magnetic particles in the microcapsules 130 which are acted by the lines of magnetic force in the vertical direction within the restricted area are migrated, and, for example, the magnetic particles migrate to the front side.

On the other hand, FIG. 5B schematically shows the lines of magnetic force in which the magnets 50, 52 protrude from the edge 44 of the holder 40. In this case, since the surfaces of the magnets 50 and 52 protrude from the edge 44, the lines of magnetic force Q from the N pole of the magnet 50 to the side wall 46 a of the holder 40 extend in the horizontal direction somewhat. When the lines of magnetic force Q extending in the horizontal direction act on the microcapsule 130, the magnetic particles in the capsule receive the magnetic force in a direction to erase, for example, the magnetic particles migrate to the back side, and instead the white nonmagnetic particles receive the magnetic force to migrate to the front side, as the result, characters are drawn by the lines of magnetic force 60 at the center of the holder 40, and simultaneously the edges of characters drawn by the outer lines of magnetic force Q at the outer edge are erased, thereby edges and outlines of images being blurred. Also, depending on the magnetic panel, the lines of magnetic force in the horizontal direction weakens the attraction force to attract the magnetic particles, so black and white are mixed in that portion, thereby the edge of images being blurred.

Further, as described in FIG. 12, even if the holder 40 is made of a metal such as a non-magnetic material, for example brass, since the lines of magnetic force of the magnets 50 and 52 include portions which exceed the radial direction of the holder and spread out in the horizontal direction somewhat, due to the above reason the lines of magnetic force in the direction to erase at the edge of the drawn images or the lines of magnetic force to weaken the attraction force of the magnetic particles is acted, therefore the characters or the like are blurred.

Next, a second embodiment of the present invention will be described. In the first embodiment, the vertical position of the magnets in the holder 40 is fixed. The magnetic pen in the second embodiment, however, has a function of varying the height of the magnets in the holder 40.

FIG. 6A is a cross-sectional view for showing the configuration of the end portion of the magnetic pen according to the second embodiment of the present invention. The second embodiment includes an adjusting mechanism 200 for adjusting the heights of the magnets 50, 52 in the holder 40. The adjustment mechanism 200 can be configured using kinds of known techniques. For example, the adjustment mechanism 200 includes a screw mechanism for changing the heights of the magnets 50 and 52 by rotating screws. In this case, a manipulating member for rotating the screw is attached so as to be available from the outside of the holder 40. Alternatively, the adjustment mechanism 200 may include a slide mechanism for changing the height of the magnets 50, 52 by sliding the slide member in up and down directions. In this case, a manipulation member for sliding is attached so as to be available from the outside of the holder 40.

FIGS. 6B and 6C show a state in which the surfaces 50 a, 52 a of the magnets 50, 52 are adjusted to the same position as the edge 44 of the holder 40 by the adjusting mechanism 200 (Δd=0). It should be noted here that the maximum position at which the height of the magnets 50, 52 can be varied by the adjustment mechanism 200 is up to the position where the surfaces 50 a, 52 a of the magnets 50, 52 do not exceed the edge 44 (Δd<=0).

In the second embodiment, by adjusting the heights of the magnets 50, 52, it is possible to vary the magnitude of the lines of magnetic force that can act on the magnetic panel 100 from the magnetic pen 10, and to adjust the thickness and density of the line segment to be drawn.

Next, a third embodiment of the present invention will be described. It is desirable that the lines of magnetic force generated from the magnetic pen 10 are incident perpendicularly to the plane of the magnetic panel 100. In the first and second embodiments, since the end portion 30 and the holder 40 are fixed with respect to the grip portion 20, the user is forced to stand the magnetic pen 10 perpendicularly to draw. The third embodiment makes it possible for the user to tilt the magnetic pen 10 in drawing while ensuring that the lines of magnetic force are incident substantially perpendicularly to the magnetic panel 100.

As shown in FIG. 7A and FIG. 7D, which shows an enlarged perspective view of FIG. 7A, the magnetic pen 10 according to the third embodiment includes a universal joint 70 for connecting the end portion 30 with the holder 40, and includes a sliding guide 80 for guiding the sliding of the holder 40. The universal joint 70 may be, for example, a ball joint as shown in FIG. 7B. The universal joint 70 includes a ball 72 formed at a tip of the end portion 30 and a rectangular bearing body 74 for connecting the ball 72. A semicircular bearing hole 76 is formed at an upper end portion of the bearing body 74 to accommodate the ball 72 slidably. Inside the bearing body 76, the holder 40 is incorporated.

The sliding guide 80 is a plate. The bearing body 74 is attached to an upper surface of the sliding guide 80 and the bottom surface slides on the magnetic panel 100. At this time, the axial direction of the magnets 50, 52 accommodated in the holder 40 in the bearing body 74 is in a relationship that its position is perpendicular to the surface of the magnetic panel 100. Preferably, the sliding guide 80 is made of a material that does not increase friction, resistance, etc. when sliding on the magnetic panel 100. In addition, the sliding guide 80 is desirably made of a transparent material so that characters or the like drawn on the magnetic panel 100 can be seen through.

The sliding guide 80 is formed, for example, in a circular shape, but may have a shape other than this (for example, a quadrangular shape). If the sliding guide 80 is made of a nonmagnetic material, the opening of the holder 40 in the bearing body 74 may be closed by the sliding guide 80. Alternatively, an opening having a size matching the shape of the holder 40 may be formed in the sliding guide 80 so that the opening of the holder 40 is exposed to the magnetic panel side. FIG. 7C shows the holder 40 and the magnets 50, 52 as viewed from the bottom side of the sliding guide 80.

As described above, according to the third embodiment, the user can tilt the grip portion 20 at an arbitrary angle when drawing, on the other hand, it is guaranteed that the axis of the holder 40 is perpendicular to the magnetic panel 100 when the sliding guide 80 on the magnetic panel 100 is slid, therefore the lines of magnetic force from the magnetic pen 10 can be effectively acted on the magnetic panel 100. Consequently, it is ensured that the line segments of letters or the like drawn on the magnetic panel 100 are clear. If the tip of the magnetic pen (or the tip of the holder) is thinned, the surface of the magnetic panel may be damaged, however, by providing the sliding guide 80, the surface of the magnetic panel is protected.

FIG. 8A shows a modified example of the universal joint. The universal joint 70A includes a pair of parallel extending portions 90 extending from the tip of the end portion 30, a rotating shaft 92 attached between the pair of extending portions 90, and a bearing body 94 rotatably supported by the rotating shaft 92. An upper end portion of the bearing body 94 is swingably connected by the rotating shaft 92.

FIG. 8B is a further modified example of FIG. 8A. In the universal joint 70A shown in FIG. 8A, the movement is restricted in the rotation direction by the rotation shaft 92. In order to eliminate this restriction, the magnetic pen shown in FIG. 8B connects the grip portion 20 with the extending portion 90 through a rotating member 96. The structure of the rotating member 96 is not particularly limited. For example, the rotating member 96 includes a columnar member and rotating shafts at both ends of the columnar member, and the rotating shafts of both ends are rotatably connected to the grip portion 20 and the extending portion 90 respectively.

FIG. 8C is a further modified example of the third embodiment. In this modified example, the center of the universal joint 70 is offset from the axis center Y 1 of the holder 40. Further, in the modified example shown in FIG. 8D, the universal joint 70 is composed of a coil spring 78 instead of the ball joint. In the example shown in the figure, the center of the coil spring 78 coincides with the axis center Y 1 of the holder 40, but the center of the coil spring 78 may be offset from the axis center Y 1 as in the case of FIG. 8C. Further, although not shown here, the universal joint 70 may be formed by using another elastic member (for example, a blade spring).

Furthermore, FIG. 8E is a modified example in which the rotating member 96 shown in FIG. 8B is applied to the magnetic pen with the coil spring 78 in FIG. 8D. As shown in the drawing, the rotating member 96 is preferably provided at the end portion 30, but the rotating member 96 may be provided at a other position (for example, a position at which the coil spring 78 is connected).

In this manner, in the third embodiment, by interposing the universal joint between the grip portion 20 or the end portion 30 and the holder 40, it is possible to make the axis of the holder 40 to be perpendicular to the magnetic panel 100 regardless of the inclination of the grip portion 20, which allows characters or the like to be drawn clearer.

Next, a fourth embodiment of the present invention will be described. In the fourth embodiment, the holder 40 is provided with a mechanism for rotating the holder 40. FIG. 9A shows a magnetic pen according to the fourth embodiment. Four cylindrical magnets 50, 52, 54, and 56 are accommodated in a holder 40 attached to the end portion 30. The N poles of the magnets 50 and 56 are exposed to the magnetic panel side; the S poles of the magnets 52 and 54 are exposed to the magnetic panel side. The N poles and the S poles of the magnets 50, 52, 54 and 56 are alternately placed in the holder 40 and are in rotational symmetry with respect to the axis of the holder 40. For example, the holder 40 is connected through a rotating member that is rotatable in the axial direction with respect to the end portion 30.

By accommodating such four magnets 50 to 56 in the holder 40, the magnetic flux density is increased, a large magnetic field can be applied to the magnetic panel 100, thus sharp characters and the like can be drawn. Furthermore, if the diameter of the holder 40 accommodating the four magnets 50 to 56 is increased, it is possible to draw characters and the like having a thicker line segment on the magnetic panel.

On the other hand, when such four magnets are arranged, the lines of magnetic force from the N poles to the S poles adjacent the axial center of the holder 40 is less likely to occur. As the result, when a line segment is drawn by the magnetic pen 10, as shown in FIG. 9C, stripes with shading unevenness are easily to occur in the diagonal directions P1 and P2. In the fourth embodiment, since the holder 40 is rotatable about the axis, when drawing by the magnetic pen 10, as shown in FIG. 9B, the diagonal directions P1 and P2 of the holder 40 are freely or arbitrarily changed, so that the shading on the drawn line segments or the like is prevented to occur.

Next, a configuration example of various magnets that can be applied to the embodiments of the present invention is shown in FIG. 10. FIG. 10A shows an example in which the magnetic body 58 is disposed in the gap or the space of the holder 40 including the magnets 50 and 52 shown in FIG. 3. By incorporating the magnetic material 58, the lines of magnetic force can be concentrated in the holder 40. FIG. 10B shows an example in which one physical shaped magnet with a S pole and a N pole on the one surface is arranged in the holder 40. FIG. 10C is a modified example of the magnet shown in FIG. 10B, in which a donut-shaped magnet having a through hole at the center is arranged in the holder 40. In this case, as well as in FIG. 10A, for example, a cylindrical magnetic body may be arranged in the space of the central portion. FIG. 10D shows an example in which one physical donut-shaped magnet having two N poles and two S poles on the one surface is arranged in the holder 40. Also in this case, for example, a cylindrical magnetic body may be arranged in the space of the central portion.

The sizes of the magnets accommodated in the holder 40 may be different from each other. For example, as shown in FIG. 10E, the N pole magnet may be larger than the S pole magnet, which are exposed to the magnetic panel, or conversely, as shown in FIG. 10F, the S pole may be larger than the N.

Furthermore, as shown in FIG. 10G, a magnetic material (for example, shaft such as a soft iron) 58 is arranged in the space between the center of the four magnets (center of the holder 40) to collect the lines of magnetic force at the central portion. Furthermore, as shown in FIG. 10H, the magnets may be arranged at a diamond shape. In this case, the internal space of the holder 40 may also have the diamond shape. Furthermore, as shown in FIG. 10I, it is also possible to arrange three magnets so that two N poles are exposed and one S pole is exposed, and as shown in FIG. 10J, it is also possible to arrange five magnets or to arrange six magnets as shown in FIG. 10K. Furthermore, as shown in FIG. 10L, a plurality of magnets, in which each magnet including a S pole and a N pole at the one surface, are arranged such that the S poles and the N poles are alternately disposed, and magnetic body 58 may also be arranged in the center.

Another embodiment of the present invention will be described furthermore. In the above embodiments, a plurality of magnets received in the holder 40 include at least one N pole and at least one S pole at the side of facing with the magnetic panel, however, in this embodiment, as shown in FIG. 11, one magnet 300 is accommodated in the holder 40. The surface of the N pole of the magnet 300 is recessed by the depth Δd from the edge 44 of the holder 40. Even in such configuration, since the lines of magnetic force from the N pole recessed by Δd are directed to the S pole through the holder 40, the lines of magnetic force are suppressed within the radius of the holder 40 and are easily extended at vertical direction, thus the magnetic field acts to the microcapsules of the magnetic panel effectively.

Furthermore, as discussed with respect to the second embodiment, the adjustment mechanism 200 for adjusting the height of the magnet 300 can be applied to the configuration shown in FIG. 11. Also in this case, it should be noted that the surface of the magnet 300 is adjusted within a range not exceeding the edge 44 of the holder 40. That is, Δd<=0.

Next, a sixth embodiment of the present invention will be explained in reference to drawings. FIG. 13A shows a sectional view of a holder of the magnetic pen according to the sixth embodiment, FIG. 13 B shows a plan view of the holder from the bottom view.

A holder 500 for the magnetic pen of this embodiment includes a generally cylindrical a holder body 510 and a magnet 520 contained in the holder body 510. The holder body 510 is made of a magnetic material such as iron, and has a circular bottom surface 510A and a cylindrical side surface 510B connected to the circular bottom surface 510A. The bottom surface 510A and the side surface 510B form a circular cylinder internal space to receive the magnet 520 therein. The magnet 520 is shaped as, for example a circular cylindrical so as to conform the shape of the internal space, and an S pole and an N pole are magnetized in its axial direction. The holder body 510 is formed with an opening 510C at the bottom surface 510A to expose a part of the magnet 520. For example, the opening 510C is shaped as a circular whose center is concentric with the axis center of the magnetic pen 10.

Next, a method for manufacturing the holder will be explained. A metal member 530 with thickness T as a precursor is prepared. The metal member 530 is then fabricated in a cup shape as shown in FIG. 13C by means of plastic forming (for example, bending, extrusion, drawing and cutting etc.). Each thickness of a bottom portion 534 and a side portion 534 of the fabricated metal member 530 is generally T. Please note that if the metal member 530 is fabricated by cutting, the thickness of the bottom portion 532 can be differed from that of the side portion 534. Next, the bottom portion 532 is formed with a circular opening 536 with a diameter W by punching or drilling as shown in FIG. 13D. Next, the circular cylindrical magnet 520 is inserted into the internal space defined by the bottom portion 532 and the side portion 534, through an upper open end of the metal member 530, as shown in FIG. 13E. Thus, the magnetic material holder 500 is obtained as shown in FIG. 13A.

The holder 500 is protruded from the one portion 30 of the magnetic pen 10 as shown in FIG. 1 when characters etc. are written on the magnetic panel. At this time, the lines of magnetic force or the magnetic field of the magnet 520 that acts on the magnetic panel is adjusted in dependence upon the size of the opening 510C formed in the bottom surface 510A of the holder body 510. In other words, the bottom surface 510A acts as a magnetic shield since the holder body 510 is made of the magnetic material, and as the size W of the opening 510C is larger, correspondingly as the lines of magnetic force of the magnet 520 is spread out in a radial direction, on the other hand, as the size W of the opening 510C is smaller, correspondingly as the lines of magnetic force of the magnet 510 is not spread out in the radial direction. A width and/or type of lines for characters and figures etc. drawn on the magnetic panel is adjusted by the proper size W of the opening 510C.

It is noted that making a fine or very small magnet is very difficult, however it is advantageous that the finer magnet is substantially available by reducing the size W of the opening 510C of the holder body 510, according to this embodiment.

Also, the surface of the magnet 520 is offset or recessed from the surface of the bottom surface 510A by thickness T. The lines of magnetic force of the magnet 520 is prevented to spread out in the radial direction more than necessary by the offset of the surface of the magnet 520 from the bottom surface 510A, whereby the edges of outlines for the drawn characters and figures is prevented to be blur. According to this embodiment, adjusting the offset of the magnet 520, and/or positioning the magnet 520 are not needed substantially. As described above, the amount of offset of the magnet 520 is ensured due to the thickness T of the bottom portion 532 when the magnet 520 is inserted into the internal space formed by the bottom portion 532 and side portion 534 of the precursor.

FIG. 13F exemplifies a modified holder according to this embodiment. In the above example, the surface of the magnet 520 is exposed from the bottom surface 510A through the opening 510C. If the protection of the surface of the magnet 520 is desired, the opening 510C may be filled with a protective member 538 of a magnetic field permeable material. If the surface of the magnet 520 is kept to be exposed, for example, magnetic dusts, magnetic powders and magnetic particles etc. in the air could adhere to the surface of the magnet 520 or inside of the opening 510C, as the result, the lines of magnetic force or magnetic field generated through the size W of the opening 510C is weaken, which causes the sharpness of drawn the characters etc. degraded.

In addition, it takes much time and efforts to remove such the magnetic powders dusts etc. from the surface of the magnet 520. It is also desirable that the protective member 538 is recessed slightly from the bottom surface 510A or is as same as the bottom surface 510A because the magnetic material holder 500 slides on the magnetic panel at the depicting, whereby the upper sheet no of the magnetic panel is prevented to be damaged and the magnetic pen 10 is slid smoothly. It is noted that the holder body 510 may be formed by means of metallic molding or cutting other than plastic forming.

Next, another modified example of magnets for the holder is shown in FIG. 14, which includes FIGS. 14A-14F. The magnetic material holder in FIGS. 14A and 14B exemplify to use the magnet 540 in which the N pole and the S pole are magnetized in the radial direction. FIGS. 14 C and 14D exemplify the two cylindrical magnets 550 and 552 contained in the holder body 510, FIGS. 14E and 14F exemplify four cylindrical magnets 560, 562, 564 and 566 contained in the holder body 510. It is noted that the above shapes, numbers and arrangements of the magnets are the examples and the present invention is not limited to such examples and may be applied with other shapes, numbers and arrangements.

Next a seventh embodiment of the present invention will be explained. FIG. 15 shows a sectional view of a magnetic pen according to the seventh embodiment. The magnetic pen 600 according to the seventh embodiment includes a housing (a grip portion) 602 in which an internal space extending in the longitudinal direction is formed, a battery 604 contained in the housing 602, a control circuit 606, a motor 608 and a magnet 610. The control circuit 606 is powered by the battery 604 and drives the motor 608 in response to the press of a switch 612 attached with the sidewall of the housing 602. The magnet 610 is a cylindrical shape, which is longitudinally extended by a predetermined length in the housing 602, and the N pole and the S pole are magnetized in the radial direction. When the magnet 610 is rotated by the driven of the motor 608, the magnetic field at the longitudinal areas and at the one end 622 of the magnet 610 is changed, whereby the characters etc. drawn on the magnetic panel are erased at the longitudinal areas or at the one end 622 of the housing 602. In addition, a cylindrical sliding member 624, which is made of a magnetic material and is movable in the axial direction of the magnetic pen 600, may be provided. The magnetic field of the magnet 610 is changed by sliding the sliding member 624 to change the erased areas.

The magnetic pen 600 has an end portion 614 at one end of the housing 602 and the end portion 614 is provided with a rotation mechanism 616. The rotation mechanism 616 is provided with a drawing portion 618. The drawing portion 618 includes a pen tip 620 with the magnet(s). The rotation mechanism 616 is allowed to rotate around the central axis C clockwise or counterclockwise, and its rotation angle is not necessarily limited or may be determined from zero degree to any degree. FIG. 16 shows an enlarged drawing portion of the magnetic pen according to the seventh embodiment. When the magnetic pen 600 is pressed on the magnetic panel 100, the rotation mechanism 616 changes the angle theta 1 and 2 between the drawing portion 618 and the end portion 614 in flexible in accordance with such as an angle theta of user's hand grasping the magnetic pen or an angle pressing it, whereby the pen tip 620 can be tilted with respect to the surface of the magnetic panel 100 (FIG. 16A) and the pen tip 620 can be upright with respect to the surface of the magnetic panel 100 (FIG. 16B).

FIG. 17 shows a modification of the pen tip according to the seventh embodiment. The drawing portion 618 in the drawing includes a pen tip 620A for drawing bold characters and a pen tip 620B for drawing fine characters. The drawing portion 618 is allowed to rotate around a center axis C of the rotation mechanism 616, and the pen tip 620A or the pen tip 620B can be contained in the tip 614. FIG. 17A shows an aspect that the pen tip 620B is contained in the tip 614. The pen tip 620B could be appeared by rotating the rotation mechanism 616 manually or automatically (FIG. 17B). Although not shown, when the pen tip 620B turns to a state in straight line such as FIG. 17A, the pen tip 620A is contained in the end portion 614. The end portion 614 and the housing 602 may be detachable by using a screw mechanism 626, and the drawing portion 618 in FIG. 15 and/or the drawing portion 618 in FIG. 16 can be replaced with others ones.

In the above embodiments, the cylindrical grip portion, the end portion and the holder are exemplified, however their shapes are not limited to the cylindrical shape. They may be other rectangular shapes or elliptical shapes. In particular, the shape of the end portion is arbitrary, and the internal space formed therein is also arbitrary. Also, the size and shape of the magnets accommodated in the holder are arbitrary. Preferably, the shape and size of the magnet are selected according to the shape and size of the internal space of the holder, or the shape and size of the internal space of the holder are selected according to the shape and size of the magnet.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments, but various other modifications and/or changes may be made without departing from the scope of the present invention described in the claims. 

What is claimed is:
 1. A magnetic pen for use in drawing arbitrary characters, figures, and symbols on a magnetic panel for a display by applying a magnetic field, the magnetic pen comprising: a body that includes an end portion; a holder made of a magnetic material attached to the end portion, an internal space formed in the holder, the holder including a bottom portion formed with an opening and a side portion connected to the bottom portion; and a magnet arranged in the internal space of the holder, the magnet received in a space formed by the bottom portion and the side portion, the magnet having a surface exposed from the opening.
 2. The magnetic pen according to claim 1, wherein a plurality of magnets are arranged in the internal space of the holder.
 3. The magnetic pen according to claim 1, wherein the opening has an adjustable size so that lines of magnetic force from the magnet can be adjusted in a radial direction.
 4. The magnetic pen according to claim 1, wherein the bottom portion and the opening both have circular shapes and the side portion has a cylindrical shape.
 5. The magnetic pen according to claim 1, wherein the surface of the magnet is recessed from the surface of the bottom portion by the thickness of the bottom portion.
 6. The magnetic pen according to claim 5, wherein the bottom portion is bent from the side portion.
 7. The magnetic pen according to claim 1, wherein the opening is filled with a protective member of a magnetic field permeable material.
 8. A magnetic pen for use in drawing arbitrary characters, figures, and symbols on a magnetic panel for a display by applying a magnetic field, the magnetic pen comprising: a body that includes an end portion; a holder made of a magnetic material attached to the end portion, an internal space formed in the holder; and a magnet having an S pole and an N pole arranged in the internal space of the holder so that the S pole or the N pole is opposite the magnetic panel, wherein an end surface of the magnet is located so as to be recessed from an edge of the holder.
 9. The magnetic pen according to claim 8, wherein the holder includes a bottom portion formed with an opening and a side portion connected to the bottom portion, the magnet received in a space formed by the bottom portion and the side portion.
 10. The magnetic pen according to claim 8, further comprising an adjusting mechanism configured to adjust a position of the magnet with respect to the edge of the holder.
 11. The magnetic pen according to claim 8, wherein the magnet includes a plurality of S poles and a plurality of N poles so as to face the magnetic panel.
 12. The magnetic pen according to claim 11, wherein the plurality of S poles and the plurality of N poles are arranged in rotational symmetry with respect to an axial center of the holder.
 13. The magnetic pen according to claim 8, further comprising a magnetic member arranged in the internal space of the holder adjacent to the magnet.
 14. The magnetic pen according to claim 13, wherein the magnetic member is disposed at an axial center of the holder.
 15. A magnetic pen for use in drawing arbitrary characters, figures, and symbols on a magnetic panel for a display by applying a magnetic field, the magnetic pen comprising: a body that includes an end portion and a grip portion connected to the end portion, wherein the end portion is connected to the grip portion through a universal joint; a holder made of a magnetic material attached to the end portion, an internal space formed in the holder; and a magnet having an S pole and an N pole arranged in the internal space of the holder so that the S pole or the N pole is opposite the magnetic panel, wherein an end surface of the magnet is located so as to be recessed from an edge of the holder.
 16. The magnetic pen according to claim 15, wherein the holder includes a bottom portion formed with an opening and a side portion connected to the bottom portion, the magnet received in a space formed by the bottom portion and the side portion.
 17. The magnetic pen according to claim 15, wherein the end portion includes a sliding guide connected to the universal joint.
 18. The magnetic pen according to claim 15, wherein the universal joint provides a two-dimensional or three-dimensional connection so that an axis of the holder is substantially perpendicular to a plane of the magnetic panel.
 19. The magnetic pen according to claim 18, wherein the end portion includes a sliding guide connected to the universal joint.
 20. The magnetic pen according to claim 15, wherein the universal joint is attached so as to offset from the center of the holder. 